There are substantial genetic contributions to the development of complex behaviors in humans and animals. The research challenge is to understand how these genetic contributions influence the developmental pathways that lead to complex behaviors of relevance to human health and disease. Developmental behavior genetics integrates the perspectives of quantitative genetics, molecular genetics, neurobiology and, increasingly, the resources of bioinformatics, into the study of behavioral development. Using multidisciplinary approaches, the genetic contributions to normal and abnormal development can be investigated. The application of biometrical genetic techniques and the development of quantitative trait loci methods allows the mapping of genes that regulate complex polygenic traits, as well as the development of quantitative information about stability and change during development and the causes of specificity and generality, or comorbidity, across behavioral phenotypes. Information from such analyses, along with neurochemical neuropharmacological, and molecular genetic studies, will provide an understanding of how gene function is related to behavioral development. The Institute for Behavioral Genetics (IBG) at the University of Colorado has actively pursued the goals of behavior genetics for nearly four decades. Its faculty is distinguished and active in research. Major research projects are now in progress in both human and animal behavior genetics. Facilities are available for gene mapping studies in human, mouse and nematode models, behavioral and biochemical studies in mice and nematodes, and biometrical analyses of extensive human phenotypic twin, family, adoption, and clinical datasets that can be cross-linked to DNA data. Funds are requested to support 5 predoctoral and 2 postdoctoral trainees. Predoctoral trainees receive doctorate degrees from a cooperating academic unit and certification in behavior genetics. Academic requirements in the training program include training in behavior genetics, quantitative and biometrical genetics, theoretical and computer-based statistics, molecular genetics, bioinformatics, responsible conduct of research, and courses on behavioral and clinical phenotypes. Additional requirements vary according to the degree granting academic unit. Research experience is an integral part of training. Postdoctoral trainees also pursue a formalized program that emphasizes individual research as well as competence in molecular and quantitative behavior genetics. Other activities in their preparation include: supervision of students and/or technicians, hosting of seminar speakers, guest lecturing, and mandatory attendance in a course on the responsible conduct of research and a weekly journal club.